Leucodepletion and the interaction of polymorphonuclear cells with endothelium in systemic inflammatory response syndrome

The abnormal interaction of polymorphonuclear cells (PMNs) with blood vessel walls is considered to underlie the multiple organ failure of systemic inflammatory response syndrome (SIRS). This consideration is supported by the present finding that PMNs from patients with SIRS are activated, as assessed by an increased distribution of cells bearing CD64, enhanced expression of CD11b and decreased expression of CD62L, and are highly adhesive to endothelial monolayers. Passage of SIRS blood through leucodepletion filters in a laboratory-designed extracorporeal circuit resulted in a marked depletion of PMNs. Of the PMNs that remained in the blood, far fewer cells bound to cultured endothelial cells in comparison with PMNs prior to leucofiltration. We propose that leucofiltration of SIRS blood will limit the number of PMNs available for binding to blood vessel walls and, hence, reduce the pathological manifestations associated with this disorder.

The effects of leucodepletion in patients who develop the systemic inflammatory response syndrome following cardiopulmonary bypass

The development of the systemic inflammatory response syndrome (SIRS) is associated with increased morbidity and mortality. Numerous anticytokine trials have failed to demonstrate any outcome benefit and there has been little evidence of improvement in the prognosis of this condition over the past 20 years. This study examines the effect of using a white cell filter designed to remove polymorphonuclear cells (PMNs) in patients who developed SIRS 36 h after cardiopulmonary bypass (CPB). Twenty-four patients were randomized to receive either leucofiltration (LF) or control therapy (CT). The two groups were well matched at study entry in terms of age, severity of illness and length of time on CPB. LF patients received 60 min filtration periods using a venovenous extracorporeal circuit at a flow rate of 200 ml/min with the cycle repeated every 12 h while SIRS and other entry criteria were met. CT patients received standard therapy. LF patients received an average of 4.2 cycles (range 1-8) and, after 15 min filtration, the total leucocyte count had fallen from 16.2 +/- 5.3 to 10.4 +/- 3.3 x 10(9)/l and PMN from 14.4 +/- 5.2 to 8.3 +/- 4.2 x 10(9)/l. The mean platelet count changed from 127 +/- 87 to 117 +/- 82 x 10(9)/l. No adverse effects related to leucodepletion were observed. There was no difference between the groups in either mortality or length of stay at the intensive care unit or at hospital discharge. Organ function was assessed regularly during the study period and significant changes occurred only in respiratory and renal function. In the LF patients, respiratory function assessed by change in hypoxaemia index from baseline and renal function assessed by serum creatinine showed significant treatment effects compared to CT patients (p < 0.01, < 0.01 respectively); three CT patients, but no LF patients, received haemofiltration during the study period. Leucofiltration safely and effectively removes circulating PMNs from patients with SIRS following CPB. This may result in improved pulmonary and renal function in these patients. Further studies are required of the kinetics and phenotypic characteristics of PMN removal by leucofiltration and a larger multicentre study will be necessary to determine whether this novel therapy has a significant outcome benefit in critically ill patients with SIRS.

Sequencing of the Francisella tularensis strain Schu 4 genome reveals the shikimate and purine metabolic pathways, targets for the construction of a rationally attenuated auxotrophic vaccine

Francisella tularensis is the etiological agent of tularemia, a serious disease in several Northern hemisphere countries. The organism has fastidious growth requirements and is very poorly understood at the genetic and molecular levels. Given the lack of data on this organism, we undertook the sample sequencing of its genome. A random library of DNA fragments from a highly virulent strain (Schu 4) of F. tularensis was constructed and the nucleotide sequences of 13,904 cloned fragments were determined and assembled into 353 contigs. A total of 1.83 Mb of nucleotide sequence was obtained that had a G+C content of 33.2%. Genes located on plasmids pOM1 and pNFL10, which had been previously isolated from low virulence strains of F. tularensis, were absent but all of the other known F. tularensis genes were represented in the assembled data. F. tularensis Schu4 was able to grow in the absence of aromatic amino acids and orthologues of genes which could encode enzymes in the shikimate pathway in other bacteria were identified in the assembled data. Genes that could encode all of the enzymes in the purine biosynthetic and most of the en- zymes in the purine salvage pathways were also identified. This data will be used to develop defined rationally attenuated mutants of F. tularensis, which could be used as replacements for the existing genetically undefined live vaccine strain.

High levels of hepatitis C virus RNA in native livers correlate with the development of cholestatic hepatitis in liver allografts and a poor outcome

A subset of hepatitis C virus (HCV)-positive liver transplant recipients develop cholestatic hepatitis (CH). We investigated the role of pretransplantation disease activity (estimated by Knodell score and HCV RNA quantitation) in the native liver explant on the development of CH and graft and patient outcome. Eight patients with CH were identified among HCV-positive liver transplants and were compared with 20 consecutive patients with recurrent HCV hepatitis of noncholestatic type in liver transplants. We evaluated all 28 explanted native livers histologically using the Knodell scoring system. HCV viral load was measured in the native explant and 5 allograft explants from the CH group using Amplicor HCV RNA Monitor test. Six of 8 patients with CH had HCV RNA levels of 5,000 copies/microg of DNA or greater in the native liver explant, whereas only 1 of the control group had viral loads greater than this level. Greater HCV RNA levels correlated with worse graft and patient survival (P <.001). The 3-year survival rate in the CH group was 18% compared with 77% in the control group (P <.001). There was no difference in the primary immunosuppressive regimens used in the 2 groups. We conclude that (1) CH has a uniformly poor prognosis, (2) type of immunosuppressive therapy appears to have little influence on the development of CH, (3) high pretransplantation HCV RNA levels in the native explant may predict the development of CH, and (4) patients with high HCV RNA levels in the explanted native liver may be appropriate candidates for antiviral therapy to prevent the development of CH.

Diastolic dysfunction: pathophysiology, clinical features, and assessment with radionuclide methods

Basic to our understanding of heart failure is the distinction between systolic and diastolic ventricular dysfunction. Diastolic dysfunction implies that the ventricle cannot accept blood at normally low pressures. The ventricular filling pattern and the relation between ventricular diastolic pressure and volume reflect a dynamic interaction between time course of relaxation, conversion of elastic forces into elastic recoil, and the passive properties of the ventricle. In the early part of diastolic filling, the pressure-volume relationship is influenced primarily by relaxation; in the latter part of diastole, passive filling properties are important. Mitral inflow patterns reflect these time-varying filling dynamics and are commonly assessed with echocardiography. Disorders of diastolic filling are observed in patients with heart failure with normal ejection fraction, myocardial ischemia, and even dilated cardiomyopathy. Patients with concentric ventricular hypertrophy, normal ejection fraction, and heart failure are the prototype of patients with diastolic dysfunction. In this article we review the physiology and pathophysiology of diastole and the main clinical disorders associated with diastolic dysfunction, and we outline in brief the application of radionuclide techniques in the assessment of diastolic dysfunction.

Stress nuclear myocardial perfusion imaging versus stress echocardiography: prognostic comparisons

The use of noninvasive stress cardiac imaging for stratifying risk in patients with known or suspected coronary artery disease is growing as a tool for identification of the subgroup most likely to benefit from the expense and risk of more invasive procedures, including cardiac catheterization and coronary revascularization. In this setting, it is especially important that a test be able to identify patients with sufficiently low risk that clinicians are comfortable in deferring such interventions, especially in those with other markers of increased risk. Previous data have shown that cardiac risk is most closely related to the presence and extent of jeopardized viable myocardium on noninvasive stress cardiac imaging. Although stress echocardiography may have comparable ability to detect coronary artery disease, current data suggest that stress echocardiography detects significantly less jeopardized viable myocardium than stress nuclear myocardial perfusion imaging and consequently fewer patients at risk for cardiac events. Stress nuclear myocardial perfusion imaging may therefore have important advantages for risk stratification and the direction of future care of patients with known or suspected coronary artery disease.

Circulating rotavirus-specific antibody-secreting cells (ASCs) predict the presence of rotavirus-specific ASCs in the human small intestinal lamina propria

Rotaviruses are the most important cause of infectious diarrhea in children throughout the world. Protection is most likely mediated by small-intestinal virus-specific IgA. However, neither fecal nor serum virus-specific IgA clearly correlates with protection against challenge. The capacity of rotavirus-specific antibodies and rotavirus-specific antibody-secreting cells (ASCs) in the circulation to predict the presence of ASCs in the intestines of children was evaluated. Mononuclear cells from intestinal biopsy samples and blood from 21 children were enriched for CD38, a marker of terminally differentiated B cells, and evaluated for the presence of virus-specific and total IgA- and IgG-secreting cells, by ELISPOT assay. Serum virus-specific IgA and IgG levels were determined by ELISA. The ratio of virus-specific to total IgA-secreting cells in the blood correlated with that found in the small, but not large, intestine. In contrast, serum rotavirus-specific IgA correlated less well with the presence of virus-specific ASCs in the small intestine.

Purification, characterization, cDNA cloning and expression of a novel ketoreductase from Zygosaccharomyces rouxii

A novel ketoreductase isolated from Zygosaccharomyces rouxii catalyzes the asymmetric reduction of selected ketone substrates of commercial importance. The 37.8-kDa ketoreductase was purified more than 300-fold to > 95% homogeneity from whole cells with a 30% activity yield. The ketoreductase functions as a monomer with an apparent Km for 3,4-methylenedioxyphenyl acetone of 2.9 mM and a Km for NADPH of 23.5 microM. The enzyme is able to effectively reduce alpha-ketolactones, alpha-ketolactams, and diketones. Inhibition is observed in the presence of diethyl pyrocarbonate, suggesting that a histidine is crucial for catalysis. The 1.0-kb ketoreductase gene was cloned and sequenced from a Z. rouxii cDNA library using a degenerate primer to the N-terminal sequence of the purified protein. Furthermore, it was expressed in both Escherichia coli and Pichia pastoris and shown to be active. Substrate specificity, lack of a catalytic metal, and extent of protein sequence identity to known reductases suggests that the enzyme falls into the carbonyl reductase enzyme class.

Bitemarks in chocolate: a case report

Police investigating a theft from a chocolate factory recovered three pieces of chocolate with irregular fractured surfaces displaying a pattern of marks made by human teeth. A highly accuracy dental impression material was used to prepare casts of these marks which were examined and photomicrographed, confirming that they had in fact been produced by human teeth. Casts and photomicrographs of the suspect's teeth were made in order to record the fine details of the casts of the dentition. Unique characteristics evident on these casts included a small notch on the incisal edge of the upper right lateral incisor, wear facets on the incisal edges of the upper central incisors and on the lower right lateral incisor and a space of approximately 1.5 mm between the upper left central incisor and lateral incisor which was rotated about 20 degrees distally. Both direct and photomicrographic comparisons between the casts of the chocolates and of the suspect's dentition revealed correspondence between their unique characteristics.

Flow cytometric analysis of different adhesion molecules expression on circulating CD14- and CD64- human dendritic cell precursors

Blood dendritic cell precursors (DCps) are identified as mononuclear leukocytes expressing HLA-DR but lacking the characteristic antigens associated with T cells (CD3), NK cells (CD16 and CD56) and B cells (CD 19). Dendritic cell precursors are distinguished from monocytes by their lack of expression of CD64 rather than of CD14. This study investigated whether CD14- DCps differed from CD64-DCps, which were predominantly CD14+, in their expression of five well-characterised adhesion molecules. There were significantly fewer cells expressing CD11b, CD18 and CD29 in the CD64-DCp population compared with CD14- DCps, and this CD64- DCp subpopulation also had a lower expression of CD11b and CD18. Our results suggest that the two DC precursor subpopulations may differ from one another in their binding characteristics to blood vessel walls and to other leukocytes.

Liver transplantation

Survival after liver transplantation has steadily improved, in part because of newer immunosuppression, which may offer decreased long-term side effects. Reduction of steroids early in the course of transplant continues to be a goal, with satisfactory results in terms of both risk of rejection and reduction of side effects. Dominating the literature and the press in 1999 was the controversy surrounding the way in which livers are allocated. Regulation by the federal government was proposed to change the way the United Network of Organ Sharing distributes and allocates livers. Prompted by the shortage of organs, living-donor liver transplantation has blossomed. Continued experience in pediatric patients has shown excellent survival rate and quality of life. In adults, further experience is being gained with respect to the use of right lobes for transplantation. Early data suggest that this is a potential alternative to cadaveric transplantation in adults, with acceptable risk to the donor. Despite advances made in improving the technical aspects of transplantation, recurrent disease remains a significant issue. Lamivudine appears to be a potent inhibitor of hepatitis B virus DNA replication after liver transplantation, although resistance remains a significant problem. Further review of transplantation for hepatitis C virus is encouraging, with excellent five-year survival rate. However, studies evaluating the evolution of fibrosis in these patients throw caution on those results, showing increased progression to cirrhosis over time. Further follow-up of these patients is needed to more accurately assess long-term impact of hepatitis C on morbidity and mortality rates after liver transplantation.

Chemical and physiological characterization of fluo-4 Ca(2+)-indicator dyes

We have developed fluo-4, a new fluorescent dye for quantifying cellular Ca2+ concentrations in the 100 nM to 1 microM range. Fluo-4 is similar in structure and spectral properties to the widely used fluorescent Ca(2+)-indicator dye, fluo-3, but it has certain advantages over fluo-3. Due to its greater absorption near 488 nm, fluo-4 offers substantially brighter fluorescence emission when used with excitation by argon-ion laser or other sources in conjunction with the standard fluorescein filter set. In vitro, fluo-4 exhibited high fluorescence emission, a high rate of cell permeation, and a large dynamic range for reporting [Ca2+] around a Kd(Ca2+) of 345 nM. We have also developed several Ca(2+)-indicators related to fluo-4 having lower affinities for Ca2+ that are useful in cellular studies requiring quantification of higher [Ca2+]. In a variety of physiological studies of live cells, fluo-4 labeled cells more brightly than did fluo-3, when challenged with procedures designed to elevate calcium levels. Fluo-4 is well suited for photometric and imaging applications that make use of confocal laser scanning microscopy, flow cytometry, or spectrofluorometry, or in fluorometric high-throughput microplate screening assays. Because of its higher fluorescence emission intensity, fluo-4 can be used at lower intracellular concentrations, making its use a less invasive practice.

Evaluating the effects of functional communication training in the presence and absence of establishing operations

We conducted functional analyses of aberrant behavior with 4 children with developmental disabilities. We then implemented functional communication training (FCT) by using different mands across two contexts, one in which the establishing operation (EO) that was relevant to the function of aberrant behavior was present and one in which the EO that was relevant to the function of aberrant behavior was absent. The mand used in the EO-present context served the same function as aberrant behavior, and the mand used in the EO-absent context served a different function than the one identified via the functional analysis. In addition, a free-play (control) condition was conducted for all children. Increases in relevant manding were observed in the EO-present context for 3 of the 4 participants. Decreases in aberrant behavior were achieved by the end of the treatment analysis for all 4 participants. Irrelevant mands were rarely observed in the EO-absent context for 3 of the 4 participants. Evaluating the effectiveness of FCT across different contexts allowed a further analysis of manding when the establishing operations were present or absent. The contributions of this study to the understanding of functional equivalence are also discussed.

Correlations among p53, Her-2/neu, and ras overexpression and aneuploidy by multiparameter flow cytometry in human breast cancer: evidence for a common phenotypic evolutionary pattern in infiltrating ductal carcinomas

Human solid tumors develop multiple genetic abnormalities that accumulate progressively in individual cells during the course of tumor evolution. We sought to determine whether there are specific sequences of occurrence of these progressive evolutionary changes in human breast cancers by performing correlated cell-by-cell measurements of cell DNA content, p53 protein, Her-2/neu protein, and ras protein by multiparameter flow cytometry in 56 primary tumor samples obtained at surgery. In addition, p53 allelic loss and Her-2/neu gene amplification were determined by fluorescence in situ hybridization in cells from the same samples. We reasoned that if there is a specific order in which genetic changes occur, the same early changes would be found consistently in the cells with the fewest abnormalities. We reasoned further that late-developing abnormalities would not occur alone in individual cells but would almost always be found together with the early changes inherited by the same cells. By these criteria, abnormalities involving p53 generally occurred early in the course of development of invasive breast cancers, whereas ras protein overexpression was found to be a late-occurring phenomenon. Within individual tumors, cellular p53 overexpression was often observed alone in individual cells, whereas ras protein overexpression was rarely observed in the absence of p53 overexpression and/or Her-2/neu overexpression in the same cells. Furthermore, the intracellular level of each abnormally expressed protein was found to increase progressively as new abnormalities were acquired. Infiltrating ductal carcinomas exhibited characteristic phenotypic patterns in which p53 allelic loss and/or p53 protein overexpression, Her-2/neu amplification and/or overexpression, aneuploidy, and ras overexpression accumulated within individual cells. However, this pattern was not a prominent feature of lobular breast cancers. All six lobular breast cancers studied were diploid. p53 allelic loss and/or early p53 overexpression, and late ras cooverexpression in the same cells were less common in lobular breast cancers than in infiltrating ductal carcinomas. Although Her-21neu overexpression was a common finding in lobular breast cancers, Her-2/neu amplification was not observed in these tumors.

Early dipyridamole (99m)Tc-sestamibi single photon emission computed tomographic imaging 2 to 4 days after acute myocardial infarction predicts in-hospital and postdischarge cardiac events: comparison with submaximal exercise imaging

BACKGROUND

Because of its brief hemodynamic effects and minor effect on determinants of myocardial oxygen demand, vasodilator stress myocardial perfusion imaging (MPI) can be applied very early after acute myocardial infarction (AMI) for risk stratification, allowing management decisions to be made earlier and thus potentially shortening hospitalization stays, reducing costs, and preventing early cardiac events. This multicenter randomized trial compared the prognostic value of early dipyridamole MPI and standard predischarge submaximal exercise MPI in patients who presented with AMI.

METHODS AND RESULTS

Patients who presented with their first AMI (n=451) were randomized in a 3:1 ratio to undergo either both an early (day 2 to 4) dipyridamole (99m)Tc-sestamibi MPI study and a predischarge (day 6 to 12) submaximal exercise (99m)Tc-sestamibi MPI study or only the predischarge study. Multivariate predictors of in-hospital cardiac events included nuclear imaging summed stress and summed reversibility scores and peak creatine kinase. For postdischarge cardiac events, multivariate predictors in patients undergoing dipyridamole MPI included only the summed stress, reversibility, and rest imaging scores and anterior MI. For a given summed stress score, the interaction of reversibility score further improved the predictive value. Dipyridamole MPI showed better risk stratification than submaximal exercise MPI.

CONCLUSIONS

Dipyridamole MPI very early after MI predicts early and late cardiac events, with superior prognostic value compared with submaximal exercise imaging. The extent and severity of the stress defect and reversibility of the defect were the most important predictors of cardiac death and recurrent MI. This technique can allow management decisions to be made earlier with regard to AMI patients and could have important economic impact if applied widely.

Conservation of a CD1 multigene family in the guinea pig

CD1 is a family of cell-surface molecules capable of presenting microbial lipid Ags to specific T cells. Here we describe the CD1 gene family of the guinea pig (Cavia porcellus). Eight distinct cDNA clones corresponding to CD1 transcripts were isolated from a guinea pig thymocyte cDNA library and completely sequenced. The guinea pig CD1 proteins predicted by translation of the cDNAs included four that can be classified as homologues of human CD1b, three that were homologues of human CD1c, and a single CD1e homologue. These guinea pig CD1 protein sequences contain conserved amino acid residues and hydrophobic domains within the putative Ag binding pocket. A mAb specific for human CD1b cross-reacted with multiple guinea pig CD1 isoforms, thus allowing direct analysis of the structure and expression of at least a subset of guinea pig CD1 proteins. Cell-surface expression of CD1 was detected on cortical thymocytes, dermal dendritic cells in the skin, follicular dendritic cells of lymph nodes, and in the B cell regions within the lymph nodes and spleen. CD1 proteins were also detected on a subset of PBMCs consistent with expression on circulating B cells. This distribution of CD1 staining in guinea pig tissues was thus similar to that seen in other mammals. These data provide the foundation for the development of the guinea pig as an animal model to study the in vivo function of CD1.

Tissue quantification of hepatitis C virus RNA with morphologic correlation in the diagnosis of recurrent hepatitis C virus in human liver transplants

BACKGROUND

Histologic findings and liver enzymes in liver transplants are often non-diagnostic of recurrent hepatitis C virus (HCV) disease. In addition, the relationship between HCV replication and the presence of recurrent HCV hepatitis after liver transplantation remains unclear. We studied liver transplant recipients to determine if quantitation of HCV RNA in liver tissue by reverse transcriptase-polymerase chain reaction (RT-PCR) correlates with histopathologic disease and/or liver enzymes.

METHODS

Twenty-six patients who received liver transplants for HCV infection were evaluated. Four sequential biopsies were analyzed for each patient. HCV RNA was extracted and quantified using the Amplicor HCV Monitor Test. Histologic examination and RNA quantitation were blinded. All available liver enzymes on the day of liver biopsy were analyzed.

RESULTS

HCV RNA quantity in liver tissue was significantly increased at the time of clinically-suspected recurrence (P < .0001). HCV RNA levels were highest in biopsies with lobular hepatitis and nonspecific inflammation, followed by biopsies with cytomegalovirus infection, chronic hepatitis, and acute cellular rejection. HCV RNA quantity had a significant correlation with increasing portal inflammation (P = .0002), decreasing amount of interface hepatitis (P = .0333), and presence of acidophilic bodies (P = .0316). Increasing HCV RNA levels significantly correlated with decreasing number of episodes of treated rejection. HCV RNA quantity did not correlate with other histologic features or liver enzymes.

CONCLUSIONS

HCV RNA levels are highest at the time of active hepatocellular destruction. Elevated HCV RNA indicates recurrence. HCV RNA quantitation may be a useful diagnostic test for determining recurrent disease and distinguishing it from other causes of inflammation, such as rejection.